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Diffstat (limited to 'arch/powerpc/sysdev/axonram.c')
| -rw-r--r-- | arch/powerpc/sysdev/axonram.c | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/axonram.c b/arch/powerpc/sysdev/axonram.c new file mode 100644 index 00000000000..2326d5dc575 --- /dev/null +++ b/arch/powerpc/sysdev/axonram.c @@ -0,0 +1,381 @@ +/* + * (C) Copyright IBM Deutschland Entwicklung GmbH 2006 + * + * Author: Maxim Shchetynin <maxim@de.ibm.com> + * + * Axon DDR2 device driver. + * It registers one block device per Axon's DDR2 memory bank found on a system. + * Block devices are called axonram?, their major and minor numbers are + * available in /proc/devices, /proc/partitions or in /sys/block/axonram?/dev. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/bio.h> +#include <linux/blkdev.h> +#include <linux/buffer_head.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/genhd.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/irq.h> +#include <linux/irqreturn.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/types.h> +#include <asm/of_device.h> +#include <asm/of_platform.h> +#include <asm/page.h> +#include <asm/prom.h> + +#define AXON_RAM_MODULE_NAME "axonram" +#define AXON_RAM_DEVICE_NAME "axonram" +#define AXON_RAM_MINORS_PER_DISK 16 +#define AXON_RAM_BLOCK_SHIFT PAGE_SHIFT +#define AXON_RAM_BLOCK_SIZE 1 << AXON_RAM_BLOCK_SHIFT +#define AXON_RAM_SECTOR_SHIFT 9 +#define AXON_RAM_SECTOR_SIZE 1 << AXON_RAM_SECTOR_SHIFT +#define AXON_RAM_IRQ_FLAGS IRQF_SHARED | IRQF_TRIGGER_RISING + +struct axon_ram_bank { + struct of_device *device; + struct gendisk *disk; + unsigned int irq_correctable; + unsigned int irq_uncorrectable; + unsigned long ph_addr; + unsigned long io_addr; + unsigned long size; + unsigned long ecc_counter; +}; + +static ssize_t +axon_ram_sysfs_ecc(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct of_device *device = to_of_device(dev); + struct axon_ram_bank *bank = device->dev.platform_data; + + BUG_ON(!bank); + + return sprintf(buf, "%ld\n", bank->ecc_counter); +} + +static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL); + +/** + * axon_ram_irq_handler - interrupt handler for Axon RAM ECC + * @irq: interrupt ID + * @dev: pointer to of_device + */ +static irqreturn_t +axon_ram_irq_handler(int irq, void *dev) +{ + struct of_device *device = dev; + struct axon_ram_bank *bank = device->dev.platform_data; + + BUG_ON(!bank); + + if (irq == bank->irq_correctable) { + dev_err(&device->dev, "Correctable memory error occured\n"); + bank->ecc_counter++; + return IRQ_HANDLED; + } else if (irq == bank->irq_uncorrectable) { + dev_err(&device->dev, "Uncorrectable memory error occured\n"); + panic("Critical ECC error on %s", device->node->full_name); + } + + return IRQ_NONE; +} + +/** + * axon_ram_make_request - make_request() method for block device + * @queue, @bio: see blk_queue_make_request() + */ +static int +axon_ram_make_request(struct request_queue *queue, struct bio *bio) +{ + struct axon_ram_bank *bank = bio->bi_bdev->bd_disk->private_data; + unsigned long phys_mem, phys_end; + void *user_mem; + struct bio_vec *vec; + unsigned int transfered; + unsigned short idx; + int rc = 0; + + phys_mem = bank->io_addr + (bio->bi_sector << AXON_RAM_SECTOR_SHIFT); + phys_end = bank->io_addr + bank->size; + transfered = 0; + bio_for_each_segment(vec, bio, idx) { + if (unlikely(phys_mem + vec->bv_len > phys_end)) { + bio_io_error(bio, bio->bi_size); + rc = -ERANGE; + break; + } + + user_mem = page_address(vec->bv_page) + vec->bv_offset; + if (bio_data_dir(bio) == READ) + memcpy(user_mem, (void *) phys_mem, vec->bv_len); + else + memcpy((void *) phys_mem, user_mem, vec->bv_len); + + phys_mem += vec->bv_len; + transfered += vec->bv_len; + } + bio_endio(bio, transfered, 0); + + return rc; +} + +/** + * axon_ram_direct_access - direct_access() method for block device + * @device, @sector, @data: see block_device_operations method + */ +static int +axon_ram_direct_access(struct block_device *device, sector_t sector, + unsigned long *data) +{ + struct axon_ram_bank *bank = device->bd_disk->private_data; + loff_t offset; + + offset = sector << AXON_RAM_SECTOR_SHIFT; + if (offset >= bank->size) { + dev_err(&bank->device->dev, "Access outside of address space\n"); + return -ERANGE; + } + + *data = bank->ph_addr + offset; + + return 0; +} + +static struct block_device_operations axon_ram_devops = { + .owner = THIS_MODULE, + .direct_access = axon_ram_direct_access +}; + +/** + * axon_ram_probe - probe() method for platform driver + * @device, @device_id: see of_platform_driver method + */ +static int +axon_ram_probe(struct of_device *device, const struct of_device_id *device_id) +{ + static int axon_ram_bank_id = -1; + struct axon_ram_bank *bank; + struct resource resource; + int rc = 0; + + axon_ram_bank_id++; + + dev_info(&device->dev, "Found memory controller on %s\n", + device->node->full_name); + + bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL); + if (bank == NULL) { + dev_err(&device->dev, "Out of memory\n"); + rc = -ENOMEM; + goto failed; + } + + device->dev.platform_data = bank; + + bank->device = device; + + if (of_address_to_resource(device->node, 0, &resource) != 0) { + dev_err(&device->dev, "Cannot access device tree\n"); + rc = -EFAULT; + goto failed; + } + + bank->size = resource.end - resource.start + 1; + + if (bank->size == 0) { + dev_err(&device->dev, "No DDR2 memory found for %s%d\n", + AXON_RAM_DEVICE_NAME, axon_ram_bank_id); + rc = -ENODEV; + goto failed; + } + + dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n", + AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20); + + bank->ph_addr = resource.start; + bank->io_addr = (unsigned long) ioremap_flags( + bank->ph_addr, bank->size, _PAGE_NO_CACHE); + if (bank->io_addr == 0) { + dev_err(&device->dev, "ioremap() failed\n"); + rc = -EFAULT; + goto failed; + } + + bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK); + if (bank->disk == NULL) { + dev_err(&device->dev, "Cannot register disk\n"); + rc = -EFAULT; + goto failed; + } + + bank->disk->first_minor = 0; + bank->disk->fops = &axon_ram_devops; + bank->disk->private_data = bank; + bank->disk->driverfs_dev = &device->dev; + + sprintf(bank->disk->disk_name, "%s%d", + AXON_RAM_DEVICE_NAME, axon_ram_bank_id); + bank->disk->major = register_blkdev(0, bank->disk->disk_name); + if (bank->disk->major < 0) { + dev_err(&device->dev, "Cannot register block device\n"); + rc = -EFAULT; + goto failed; + } + + bank->disk->queue = blk_alloc_queue(GFP_KERNEL); + if (bank->disk->queue == NULL) { + dev_err(&device->dev, "Cannot register disk queue\n"); + rc = -EFAULT; + goto failed; + } + + set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT); + blk_queue_make_request(bank->disk->queue, axon_ram_make_request); + blk_queue_hardsect_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE); + add_disk(bank->disk); + + bank->irq_correctable = irq_of_parse_and_map(device->node, 0); + bank->irq_uncorrectable = irq_of_parse_and_map(device->node, 1); + if ((bank->irq_correctable <= 0) || (bank->irq_uncorrectable <= 0)) { + dev_err(&device->dev, "Cannot access ECC interrupt ID\n"); + rc = -EFAULT; + goto failed; + } + + rc = request_irq(bank->irq_correctable, axon_ram_irq_handler, + AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device); + if (rc != 0) { + dev_err(&device->dev, "Cannot register ECC interrupt handler\n"); + bank->irq_correctable = bank->irq_uncorrectable = 0; + rc = -EFAULT; + goto failed; + } + + rc = request_irq(bank->irq_uncorrectable, axon_ram_irq_handler, + AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device); + if (rc != 0) { + dev_err(&device->dev, "Cannot register ECC interrupt handler\n"); + bank->irq_uncorrectable = 0; + rc = -EFAULT; + goto failed; + } + + rc = device_create_file(&device->dev, &dev_attr_ecc); + if (rc != 0) { + dev_err(&device->dev, "Cannot create sysfs file\n"); + rc = -EFAULT; + goto failed; + } + + return 0; + +failed: + if (bank != NULL) { + if (bank->irq_uncorrectable > 0) + free_irq(bank->irq_uncorrectable, device); + if (bank->irq_correctable > 0) + free_irq(bank->irq_correctable, device); + if (bank->disk != NULL) { + if (bank->disk->queue != NULL) + blk_cleanup_queue(bank->disk->queue); + if (bank->disk->major > 0) + unregister_blkdev(bank->disk->major, + bank->disk->disk_name); + del_gendisk(bank->disk); + } + device->dev.platform_data = NULL; + if (bank->io_addr != 0) + iounmap((void __iomem *) bank->io_addr); + kfree(bank); + } + + return rc; +} + +/** + * axon_ram_remove - remove() method for platform driver + * @device: see of_platform_driver method + */ +static int +axon_ram_remove(struct of_device *device) +{ + struct axon_ram_bank *bank = device->dev.platform_data; + + BUG_ON(!bank || !bank->disk); + + device_remove_file(&device->dev, &dev_attr_ecc); + free_irq(bank->irq_uncorrectable, device); + free_irq(bank->irq_correctable, device); + blk_cleanup_queue(bank->disk->queue); + unregister_blkdev(bank->disk->major, bank->disk->disk_name); + del_gendisk(bank->disk); + iounmap((void __iomem *) bank->io_addr); + kfree(bank); + + return 0; +} + +static struct of_device_id axon_ram_device_id[] = { + { + .type = "dma-memory" + }, + {} +}; + +static struct of_platform_driver axon_ram_driver = { + .owner = THIS_MODULE, + .name = AXON_RAM_MODULE_NAME, + .match_table = axon_ram_device_id, + .probe = axon_ram_probe, + .remove = axon_ram_remove +}; + +/** + * axon_ram_init + */ +static int __init +axon_ram_init(void) +{ + return of_register_platform_driver(&axon_ram_driver); +} + +/** + * axon_ram_exit + */ +static void __exit +axon_ram_exit(void) +{ + of_unregister_platform_driver(&axon_ram_driver); +} + +module_init(axon_ram_init); +module_exit(axon_ram_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>"); +MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE"); 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